Flocking apparatus



Feb. 8, 1944. c W -A 2,340,850

FLOCKING APPARATUS v Filed July-2, 1943 3 Sheets-Sheet 1 BY {we aszmnszam Feb. 8, 1944. Q WQLFSON 2,340,850

FLOGKING APPARATUS Filed July 2, 1943 3 Sheets-Sheet 2 FIE-5 iz-an- IN VEN TOR; 6399620 Feb. 8, 1944. c. WOLFSON- ETAL FLOCKING APPARATUS Filed July 2, 1945 s Sheets-Sheet 5 AVAUAVAUAUAVAVAWV "II III! II iravnvA PIE. 5;

Patented Feb. 8, 1944 FLOCKING APPARATUS Charlotte Wolfson and Bella Treistman, New York, N. Y.

Application July 2, 1943, Serial No. 493,292

7 Claims.

This invention relates to apparatus for flocking, and particularly to apparatus for applying quan titles of flock to predetermined portions of selected materials for the purpose of producing a raised plush or velvet effect.

A commonly known method of applying flock is to dust or spray it on to the work to be processed at predetermined portions thereof, such portions having previously been coated with a mucilaginous substance to which the flock will adhere. Upon the completion of the process, the flocked portions of the processed material is distinguishable from other portions thereof by a more or less velvety texture. In employing such a system it has been found that the particles of flock are not always equally distributed over the area to which they are applied, and accordingly various vibrating methods have been resorted to with the intention of enabling a layer of flock to be evenly distributed.

According to certain known conventional methods of imparting a vibratory agitation to a layer of flock operatively deposited on the surface of the work being treated, a reciprocating motion is imparted to the work by placing it in a manually or mechanically reciprocated receptacle. It has, however, been found that due to the lightness of the fibers, the vibratory motion is insufficient to prevent clusters of the flock from being dislodged from the adhesive in which they happen to be embedded. To elfect a better distribution of the flock, particularly when the work to be processed is of flexible material, polygonal bars are rotated against the underside of the work, or against the underside of a flexible support for the work. The polygonal surface of the bar causes a periodic raising of the work being processed every time a corner of the bar engages the material, the number of elevations of the work per revolution of the bar corresponding to the number of faces thereof. Although it has been found that with a number of such bars, in spaced relation, improved results are sometimes obtainable, this method, nevertheless, has not succeeded in eliminating clusters of flock and an uneven distribution of the flock fibers along the adhesive-coated areas. The reason for the failure of this method to effect a substantial improvement over the older known method has been due to the fact that the linear elevation of the work corresponds to the difference between the high and low points of the bar, that is, to substantially the difierence between the short radius of the bar (to the flat surface thereof) and the long radius thereof (to the comer or intersection of two adjoining faces). Thus, with each rotation of the bar, there is imparted to the work a number of impulses raising the work only a relatively short distance, insuificient to cause a substantial disturbance of the flock adhesively held to the material. In other 50 impacts.

(c1. snj-s) words, the impulses are not sufficlent to dislodge the flock stuck to the mucilaginous material, causing only a re-arrangement of those particles of flock which are not securely held by the adhesive.

It is Within the contemplation of this invention to improve upon the known conventional methods for eifecting an equal distribution of flock, by causing the particles of flock to be dislodged-from 10 the adhesive by a succession of impacts of relatively great frequency, and whereby the intensity of each impact will be suificient to disengage all but the most firmly anchored flock fibers from the adhesive. The method is such as to cause the flock particles to be projected upwardly into the air, whereupon they will return to the work being treated in the form of a shower. This shower of independent flock particles causes an equal distribution thereof over the entire area of the work being treated, clusters being disentangled from each other and properly redistributed. And in this aspect of our invention it is a further object to enable such equal distribution and redistribution to be effectuated without the use of any reciprocating or rocking action.

In the accomplishment of the above-referredto objective of our invention, we employ, as a support forthe work being processed, a material of such properties'as to have its oWn frequency of so vibration when subjected to a suitable amount of tension. By imparting periodic impulses .to such vibratory material, the frequency of vibration can be made considerably greater than that heretoforeproduced by other methods. The action of such vibratory material issubstantially like that of a stretched drum skin. It has been found that this high frequency, when transmitted to the flock-covered Work, is suiiicient to cause the superimposed flock to be projected into the air vertically in thev form' of a shower, in the vention, an arrangement of polygonal bars similar to that known in the art, for imparting periodic impulses to the stretched vibratory materialthereby causing said vibratory material to vibrate in accordance with its own frequency between We have also found that with this method a greater tensioning of the vibratory material can be eifected by applying manual pres,- sure to selected portions of the vibratory material, the increased tension causing a correspondingly higher travel of the particles of flock, all in a manner tobe more specifically hereinafter set forth. 1

It is another object of this invention to provide a smooth surface to the vibratory material, so as to to prevent an adhesion betweenthe work being processed and the supporting vibratory material. We have found that with such an arrangement the oscillations of the vibrating material will be imparted to the work being processed, without interference, enabling 'haphazardly disposed flock to be reshufiled and straightened, and enabling the upwardly projected particles to travel a sufficient distance for best operative results.

It has always been a desirable objective in flocking processes to obtain a deep pile .of flock so as to simulate an expensive velvetb oth in 'ap-- pearance and texture. It has, however, been found that the conventional vibratory-methods have not been able to produce this effect because the impulses or vibrating action have not been sufficient to accomplish more than a limited displacement laterally of the fibers of flock. As a. result,'the flock was applied inrandom fashion, without any uniformity in their disposition along the treated area, some fibers being disposed horinot sufficient to cause the fibers to stand on end.

It is an important object .of our invention to so apply the old and well-known method of electrically charging flock particles as to render the mutually repellant action of these particles effective in producing vertically disposed flock fibers adhesively secured to the work. By our method of imparting impulses to the flock so as to project them upwardly from the work, we have found that the charged particles are vertically disposed and parallel to each other upon returning, through the air, to the work being treated. The result of our method is a flocked surface of a very deep upstanding pile, simulating in appearance and texture a high grade of velvet.

It is another object of our invention to enable.

the flock to be firmly anchored to the adhesivecoated areas. This is effectively accomplished by our method due to the fact that the particles, after being projected upwardly, fall from a sufficient height to enable them to embed themselves into the mucilaginous surface.

Another object of our invention is to enable flock of different colors to be employed without any inadvertent or accidental mixture of colors. This is accomplished by providing the vibratory material with a smooth upper surface, which will enable previously employed flock to be readily and completely removed before employing new flock.

vent the loss of fiock without interfering with the operators observation of the process and without interfering with such manual manipulation as maybe necessary for properly practicing the method of our invention.

And a further object of our invention is to enable the aforesaid objectives to be obtained in a simple, inexpensive. and easily operable manner.

Other objects, features and advantages will appear from the drawings and the description hereinafter given.

Referring to the drawings,

Figure 1 is a perspective view of a preferred form of apparatus for practicing the system of It is a further object of our invention to pie-- grammatic sectional view, taken substantially along line .3.3 of Figure 2, showing the position .of the'work and flock while the device is in operation.

' Figure 5 is a view substantially like that of Figure. 4, but showing the arrangement when the device is manually manipulated in accordance with a preferred method of practicing our .in-venion.

Figure 6 is an enlargeddiagrammatic representation of a fragment of Figure 5, with the hands removed, illustrating the shower of flock produced by our system-and the position of flock particles within the work.

Figure 7 :is a diagrammatic representation of a vibratory support for the work, .the support being shown drawn taut and elevated by the high portion or corner of a rotating polygonal bar.

Figure 8 is a view substantially like Figure '7, illustrating diagrammatically the extreme positions of the vibratory support during an operative oscillation immediately after the polygonal bar had been operatively rotated from the position of Figure '7, and

Figure!) illustrates diagrammatically ,a vibrating portion of the support of Figures? and 8 when engaged by the fingers of an operator.

Referring to the drawings which illustrate a preferred apparatus for practicing our invention, a receptacle I0 is provided, the bottom 'H of which consists of avibratory support for the'work l2 resting thereupon, the said support H being anchored to the lateral walls [.3 of the receptacle and maintained in a taut condition, allin a manner to be more' specifically hereinafter set forth.

The said receptacle is removably supported by the uprights 14, the particular arrangement illustra'ting bars I5 in slidable engagement with rail, portions I15 of said uprights. The uprights :are positioned upon a table I! preferably of a height suitable for the convenience of the operaors.

The said uprights support the three rotatable polygonal bars I8, Band 28 which are so disposed as to be frictionally engageable'with the underside of said vibratory support II when operatively rotated. The said bars have mounted thereupon pulleys 2!, 22 and '23, .and are connected by belting 24 whereby the rotation of bar 18 will be operatively transmitted to the other two bars. Bar 8 is provided with another pulley 25 which is operatively connected by belt '26 "to *motor 21.

It is required that the vibratory support H be of such properties that when stretched it will be able to vibrate in accordance with its own natural frequency upon operatively receivin one or more impacts. The nature of such vibratory material is substantially like that of a stretched membrane or drum skin which will obviously vibrate when struck by some mechanical means. It is preferred, for best operative results, that the upper surface of said vibratory support be very smooth or glazed, inasmuch as we have found that such a smooth surface will enable the vibratory support I I most effectively to transmit its oscillations to the work I 2. It hasv been found contraction or tensioning of sheet 28. condition it is thus apparent that the sheet of that a rough, coarse or fibrous upper surface of vibratory support would cause the work to adhere thereto to a suflicient extent to give unsatisfactory results. Furthermore, a glazed or smooth upper surface of the vibratory support be slidably removed from the uprights l4, and

all flock particles dumped out by inverting the receptacle, there being no adhesion between the flock particles and the smooth upper surface. In this way, differently colored flock can be successfully employed without inadvertent mixture of colors.

We have found that a suitable vibratory support can be made from a sheet of duck, canvas or other structurally strong material, the upper surface of which is provided either with a rubber sheet of a material similar to that commercially known as Pliofilm, or with a sheet of oilcloth properly secured in place. Due to the scarcity of suitable rubber materials, we have resorted to oilcloth, and found that it can be adhesively applied to a sheet of duck material, or the like, to produce a taut vibratory support provided the materials are properly treated and secured together.

In one method of practicing our invention, we attach a sheet of duck material 28 to the sides 13 of the receptacle ID by means of tacks 29, although other suitable attaching means can be employed within the scope of this invention. The sheet 28 is then treated by applying thereto a suitable glue which upon drying will cause a conpressed thereupon preferably by a hot flat iron,

the smooth surface of the oilcloth being on top. This operation results in a complete drying of the said glue 3% thereby preventing any further In this oilcloth 30 and sheet 28 will continue to remain in fixed relation to each other, in view of the fact that no further tensioning occurs, as aforesaid. The two sheets are firmly secured together throughout their entire extent, the glue preventing the formation of air pockets which would adversely affect the operative efiiciency of the device. The sheet of oilcloth 30 is then suitably attached to the sides is of the receptacle, thermoplastic tape 32 having been found suitable for such purpose.

In practicing our invention, the work l2 has applied thereto, by conventional stencil means not shown on the drawings, an adhesive in the predetermined pattern upon which the flock is to be applied. In the drawings the adhesive coated areas are identified by the reference numeral 33, the adhesive being of any composition capable of adhesively anchoring thereto particles of flock.

tension within the vibrating medium The work, with the adhesive coated pattern, is then placed within receptacle l0 upon the vibratory support H, and the motor set into oper ation. The polygonal bars, l8,l9 and 20 will accordingly engage the undersurface of the vibratory support II, and cause periodic elevations thereof whenever the corners 34 of the bars strike said support. In accordance with the method of our invention, the'rotational speed of the bars is suflicient to produce successive impacts upon the vibratory support each time a corner 34 comes into engagement therewith. It has been found that when the vibratory support II is fully tenioned, each one of the impact sets the support into vibration according to its own natural frequency. By referring to Figure'l, which together with Figures 8 and 9 illustrate the principle of operation of'our invention, it will be observed that corner 34a of bar 35 is shown in engagement with vibratory support Ha. In the position of bar 35 as indicated in Figure 8, a flat portion 36 of the bar is parallel to the support Ha, the said support bein momentarily under less tension than in Figure 7. The effect of the contion, thereby setting it into vibration between th supports or anchors 31. The vibrational effect is diagrammatically, shown bybroken lines in Figure 8. The frequency of vibration of membrane Ila is greater than the frequency of impacts of corners 34a, there producing a plurality of oscillations of the membrane between each impact.

By referring back to Figure 4, it will accordingly be seen that each time the bars l8, l9 and 20 engage and leave the support I I, vibrations thereof will occur in accordance with its natural frequency. These vibrations are transmitted to the work [2, upon which is deposited a layer 38 of flock. We have discovered that due to the relatively high frequency of vibration, the particles 38a of the flock will be thrown upwardly,

-' to return in the form'of a shower, substantially as indicated in Figure 4. The more taut the material, the higher will be the projection of the flock particles into. the air. The effect is to cause not only a considerable agitation of the layer of flock, but also a redistribution thereof over the surface of the work. And wherever the flock particles engage adhesive areas, the particles remain anchored thereto in agenerally vertical direction.

For best operative results we have found it helpful to manually manipulate the vibratory support in such a manner as to increase the tension thereof, whereupon the particles of flock are thrust considerably higher. Figure 5 illustrates the position of the fingers of operators hands causing depressions 39, 40, 4| and 42, therein. It will be seen that the distance between depression 39 and bar I8 is less than the distance be tween said bar I 8 and the next adjacent wall l3. Similarly the distance between bar I8 and depression 40 is relatively small, as well as the distance between the other bars and the shown depressions. It is obvious that due to the shortened distances between the depressed portions and the impact-producing bars l8, l9 and 20, the frequency of oscillations will be correspondingly increased; and it is also apparent that the will also be increased. We have actually found that by such manual manipulation, a higher pitch and an increased volume of sound are produced, thereby indicating .an increased-frequency and amplitude of vibration. By continuously manually manipulating various portions of the vibrating support with the work thereover, particles of flock are-made to rebound upwardly a very considerable distance, to return in the form of a fine shower of independent particles 38a. The increased frequency and amplitude of vibration are apparently the cause of this fine shower of flock particles. In the preferred method of practicing our invention, we accordingly continually apply such manual means and produce more effective results.

By referring to Figure 9 this principle is further illustrated, the depressions 43 and 44 cansing a reduction in the length of the vibrating medium to increase the frequency thereof.

Due to the frictional engagement of the rotating bars-with the underside of the vibratory support, static electricity is generated, the particles of flock each receiving like electrical charges. This principle has been known for many years, but it has never been successfully applied in flocking in view of the fact that the force of repulsion between the electrically charged particles is generally insufficient to cause them to reform their positions when firmly anchored within the adhesive areas. But in our system, where the particles are projected upwardly in the form of a' shower, the independent charged particles align themselves parallel to each other while in the air, as illustrated in Figure 6, and thereafter drop upon the work in vertical formation. The mutual repellant action is not interfered with while the particles are in the air thereby making such alignment possible.

The resultant flocked area, is hence composed of upstanding fibers equally distributed, producing a deep pile and a uniform texture. It has been found that the results obtained by this method are far superiorthan heretofore obtained by other methods, and it is believed that this result is primarily due to the production of oscillations within a vibratory support for the work, according to the natural frequency of said support-the impact means producing such oscillations also providing the necessary friction to produce charges of static electricity within the flocked particles.

The height to which the particles of flock are projected is such that we have found it necessary to provide means to prevent such particles from being thrust out of the receptacle. We have accordingly provided a peripheral canopy 45 supported by the top of the receptacle ID, the canopy having downwardly and inwardly sloping walls 46 which prevent the flock particles near the sides 13 from leaving the receptacle.

vIt is of course understood that other additional forms and modification of the apparatus and adaptations of the method constituting this invention can be employed beyond and in addition to those hereinbefore described, all within the scope of the appended claims.

What we claim is:

1. In a flocking device, an open-topped laterally enclosed receptacle, and a stretched vibratory support forming the bottom of the receptacle and adapted to support the work to be flocked said support having a smooth, upper surface.

2. In a flocking device, an open-topped laterally enclosed receptacle, -a stretched vibratory support formlngthe bottom of the receptacle and adapted to support the work to be flocked, im-

pact means operatively engageable with and adapted to intermittently actuate the support, and means to actuate said impact means, said support having a smooth upper surface.

3. In a flocking device, a stretched vibratory support adapted to support the work to be flocked, walled means surrounding said support and extending upwardly therefrom, the support being operatively secured to said walled means, rotatable polyhedral impact means in operative engagement with the underside of said support, and meansto rotate said polyhedral means at predetermined speeds, whereby the vibrations will be transmitted to the work, the period of vibration of the support being greater than the frequency of operative engagement of the impact means with the support, the upper surface of the support being smooth.

4. In a flocking device, a stretched vibratory support adapted to support the work to beflocked, a mounting for said support, impact means operatively engageable with and adapted to intermittently actuate the support, and means to actuate said impact means, said vibratory support comprising a lower layer of stretched fabric anchored to the mounting, and an upper layer of material adhesively secured to the lower layer along the entire extent thereof, the upper layer having a smooth upper surface, whereby there will be no adherence between the flocking material and the support.

5. In a flocking device, a stretched vibratory support adapted to support the work to be flocked, a mounting for said support, impact means operatively engageable with and adapted to intermittently actuate the support, and means to actuate said impact means, said vibratory support comprising a lower layer of stretched fabric anchored to the mounting, an upper layer of material, and an intermediate layer of flexible adhesive securing the upper layer throughout its extent to the lower layer, the upper layer having a smooth upper surface, whereby there will be no adherence between the flocking material and the support.

6. In a flocking device, a laterally enclosed receptacle containing a bottom wall comprising a stretched vibratory support adapted to support the work to be flocked, means removably supporting the receptacle, a plurality of spaced impact means operatively engageable with and adapted to intermittently actuate the underside of the support, and means to actuate said impact means,

said vibratory support comprising a lower layer of stretched fabric anchored to the sides of the receptacle, an upper layer of material having a smooth upper surface, whereby there will be no adherence between the flocking material and said surface, and an intermediate layer of a glue of latex composition adhesively securing the upper layer throughout its extent to the lower layer.

7. In a flocking device, a stretched vibratory support adapted to support the work to be flocked, and walled means to which said support 

